fix(codex): harden routed apply_patch contracts - #1623

Why

Current dev already contains the shared nudge fix and the fail-closed guard for undeclared routed tool calls. This PR hardens the remaining OpenCodex-owned apply_patch contract and makes future adapter additions inherit that contract automatically.

C+ adapter architecture

This PR replaces the reflective adapter-completeness test with one production authority:

• src/adapters/contracts.ts defines the finite adapter wires and mandatory routed tool contracts.
• src/adapters/registry.ts is the authoritative adapter universe and factory boundary.
• resolveAdapter() constructs adapters only through that registry.
• Azure / Azure OpenAI strictly inherit the OpenAI Responses semantic contract.
• MiMo strictly inherits the OpenAI Chat semantic contract.
• Cursor stays direct because it owns a distinct runTurn path and a gated native-file fallback.

Every registered adapter inherits these contracts with no opt-out:

• tools.code-mode-nested-helper
• tools.freeform-exact-roundtrip
• tools.tool-choice-final-catalog
• tools.continuation-replay

apply_patch is the canonical executable fixture for those generic tool-fidelity semantics. It does not become an adapter API.

Production hardening

Routed Codex catalog rows default a missing apply_patch_tool_type to "freeform" while preserving an explicit value from the upstream/template row. This keeps routed defaults safe without overriding an explicit compatible "function" representation.

Persisted/provider adapter IDs remain untrusted strings. Runtime construction validates them through the registry lookup instead of widening config types or adding circular dependencies.

Authoritative conformance gate

tests/apply-patch-conformance.test.ts derives its cases from ADAPTER_REGISTRY, so a new adapter automatically becomes a new conformance subject.

The harness uses real production adapters plus deterministic protocol-keyed upstream fixtures and verifies:

1. routed catalog exposure, missing-value defaults, and preservation of explicit tool representation;
2. nested Code Mode tools.apply_patch(...) visibility in the final provider request;
3. no provider-visible guidance that forbids an available patch helper;
4. final tool_choice semantics, including native wire-level none modes;
5. exact custom/freeform identity and hostile patch-body restoration;
6. fragmented streaming through the real adapter parser and Responses bridge;
7. buffered parsing whenever the concrete adapter exposes parseResponse;
8. exact next-turn continuation/replay;
9. Cursor mutation ownership and the gated native fallback;
10. strict wrapper-parent validity and wrapper-cycle rejection;
11. provider/model adapter configuration IDs being members of the registry;
12. compile-time AdapterWire driver completeness;
13. Bun parser-based anti-bypass checks preventing server, router, or lab conformance construction outside the registry;
14. mutation/self-tests proving representative broken observations fail the expected contract.

Responses-native adapters are tested through their real passthrough request contract rather than being forced through a parser they do not use in production. Cursor has focused runTurn coverage with a deterministic transport that verifies fragmented apply_patch input is preserved byte-for-byte. MiMo conformance injects a deterministic JWT provider through the registry, so request construction does not call the Xiaomi bootstrap endpoint.

Focused historical regressions retained

The generic C+ gate complements the existing high-resolution regression tests:

bun test tests/apply-patch-conformance.test.ts
bun test tests/apply-patch-cursor-registry-runturn.test.ts
bun test tests/apply-patch-code-mode-regression.test.ts
bun test tests/apply-patch-routed-safety-net.test.ts
bun test tests/apply-patch-adapter-nudge-regression.test.ts
bun test tests/apply-patch-cursor-mutation-policy.test.ts
bun test tests/apply-patch-catalog-contract.test.ts
bun test tests/apply-patch-responses-native-contract.test.ts

The old apply-patch-adapter-nudge-completeness.test.ts source parser is intentionally removed. Registry membership now supplies the adapter universe directly.